Shoe for oil well packers



. J. 1 SIMMONS snow FOR OIL WELL PACKERS Aug. 29,1939.

Filed June 10, 1938 I ":Q NVE TO Patented Aug. 29, 1939 PATENT OFFICESHOEFOR OIL WELL PACKERS John T. Simmons; Casper, Wym, assignor to'Halliburton Oil Well cementing Company,

Duncan, Okla.

Application June 10, 1938, Serial No. 212,881

4 Claims. (01. 166-10) This invention relates to packers adapted for usein oil wells and more particularly to shoes adapted to be associatedwith a rubber packer.

Packers are used for various purposes in connection with oil wells andare usually referred to as wall packers, hook wall packers or rat holepackers. The term wall packer is usually applied to a cylindrical rubbersleeve mounted on a mandrel and adapted to engage the wall of the holeat an uncased portion thereof to effect a seal between the mandrel andthe wall. A hook wall packer is somewhat similar to a wall packer but isprovided with slips or similar devices for engaging casing and thepacker is so designed as to effect a seal within the casing. By the termrat hole packer a cone shaped packing is usually meant and theconstruction is usually somewhat similar to that shown in the patent toSimmons, No. 1,930,987, granted October 17, 1933, for Method andapparatus for testing the productivity of formations encountered inwells.

The present invention is primarily concerned with wall packers, althoughit will be obvious to those skilled in the art that the principles ofthe invention may be applied to other types of packers as well.

It is common experience to find that after a packer has been set in awell and subsequently removed therefrom it has been torn or ruptured sothat it cannot be used again. This is especially true with respect towall packers because the wall of the hole with which they engage whenset in the well is often rough and provided with sharp obstacles. Thiscondition is further aggravated due to the fact that the rubber of thepacker is often squeezed around the shoes-normally provided. at the topand bottom of the rubber. At the high temperatures prevailing in deepwells and with the rubber subjected to the terrifllc pressure whichprevails in deep wells, it will exude through small crevices'or spacesand is commonly said to behave much like a liquid. The shoes which areordinarily provided for use in expanding the packer, being of a diametersufficiently small to prevent the possibility of their being stuck inthe open hole, are of little effect in preventing the rubber fromextending therebeyond as the packer is set.

It is an object of the present invention to provide a lower shoe for usein connection with a packer which will expand radially as the packer isset so as to prevent the rubber of,the packer from creeping beyond theshoe.

It is a further object of theinvention to provide a shoe for a packerwhich will effectively prevent the rubber from creeping downwardly andwhich will nevertheless be easily removed from the well when the packeris collapsed.

It is a further object of the invention to provide a shoe for a packerwhich will effectively protect the rubber of the packer and prevent itfrom tearing orrupturing as it is being set or removed from a well.

It is a further object to provide a lower shoe for a packer which willeffectively center the packer with respect to the'bore of the well asthe packer is being set therein.

Other objects and advantages reside in certain novel features of thearrangement and construction of parts, as will be apparent from thefollowing description taken in connection with the accompanying drawing,in which:

Figure 1 is a view in side elevation of a formation testing assemblywhich includes a wall packer provided with a shoe constructed inaccordance with the principles of the present invention;

Figure 2 is an enlarged fragmentary view of the lower portion of thepacker shown in Figure 1 and of the shoe associated therewith, this viewshowing the parts in the position which they takewhile being loweredinto the well;

Figure 3 is a view similar to Figure 2, but show ing the position whichthe parts occupy when the packer is set; and

Figure 4 is a fragmentary transverse 'crosssectional view of theapparatus in Figure 3, the view being taken on the line 4-4 thereof.

Referring to the drawing in detail, and first to the arrangement ofFigure 1, it will be seen that the assembly there illustrated includesthe lower portion of a section of drill pipe II to which a formationtester is connected. The present invention-is adapted for use whereverpackers are. employed in a well, but for the purpose of illustration theinvention is shown in connection with a formation tester because thedifliculties mentioned above are perhaps encountered more often inconnection with the tester than anywhere else. The formation tester maybe of the general type disclosed in the patent to Simmons, No. 1,930,987referred to above. However, the arrangement illustrated is more likethat of Figure 5 of the Halliburton Reissue Patent No. 20,688, grantedApril 5, 1938, for Apparatus for testing oil wells", in that theHalliburton J-type tool is illustrated herein and a wall packer isillustrated.

In Figure 1 of'the present drawing the tester proper is illustrated atl2, the packer at Hand the perforated tool or strainer at [4.

As noted above, the present invention relates primarily to theconstruction of the shoes for the packer and these are shown in enlargeddetail in Figures 2, 3 and 4. The packer I 3 consists of a cylindricalbody of rubber mounted upon a central mandrel l5 which is connected tothe perforated pipe lfl which rests upon the bottom of the well. Whenthe assembly is lowered into the well, therefore, the mandrel l5 acts asa support for the lower shoe of the packer so that when the upper shoeis forced downwardly the packer is expanded into engagement with thewall of the hole and set. The lower shoe of the packer includes atapered or conical collar l6 which is secured to the mandrel 55. A ringH is placed upon the mandrel just beneath the packer l3 and the collarHi and ring I! are separated by means of two or more saucer-shapedmembers or discs I 8 and i9. These saucers are made of spring steel andare provided with a number of radially extending slots 20. The saucersare so assembled with respect to each other that the slots in one bear astaggered relation to those in the other as v illustrated in Figure 2.

- The parts occupy the position shown in Figure 2 when being loweredinto the well. In this position it will be seen that the saucer membersI 8 and I9 have suificient curvature that they do not contact the wallsof the well and are within the confines of the collar It and ring I! inso far as the radial dimension is" concerned.

As further shown in Figure 2, it will be seen that the saucer membersare so mounted that their rims are lower than their base portions, thebase portion of the upper saucer member l8 abutting against the ring Hwhile the rim of the lower saucer member is abuts against the collar Hi.

When the packer is expanded the parts take the position shown in Figure3. It will be seen that in this figure the saucer members l8 and 19 areflattened out so as to be expanded radially well beyond the confines ofthe collar l6 and ring I'l. The saucers l8 and is may even bite into theformation slightly but whether this takes.

place or not they constitute a material aid in confining the rubber ofthe packer E3 to its proper location.

When it is desired to remove the packer from the well no difliculty isencountered. The saucers I 8 and I9, being made of spring steel, returnto the position shown in Figure 2 as soon as the packer I3 is lifted.

If desired, a coil spring may be placed around the mandrel just beneaththe lower saucer member Hi to aid in causing the saucer members l8 andI9 to assume the position shown in Figure 2 after the packer is lifted,but this coil spring will ordinarily not be necessary if the saucermembers are constructed of a good grade of spring steel.

- It will be seen from the above description that well due to the factthat as they are compressed 5 longitudinally they engage the walls ofthe hole.

While only one embodiment of the invention has been shown and describedherein, it is obvious that various changes may be made in thearrangement and construction of parts without departing from the spiritof the invention or the scope of the annexed claims.

I claim:

1. A shoe for rubber packers or the like adapted for use in oil wells,including a plurality of saucer-shaped members disposed one aboveanother, said members being made of spring steel and having a number ofradial slots therein, the slots in one member being staggered withrespect to those in another member, the arrangement being such that uponpressure being exerted on said members, they expand radially and providemeans for preventing the packer from flowing or creeping past the shoethereof.

2. A shoe for oil wellpackers or the like, including a saucer-shapedmember having a number of radial slots therein, said member beingmountedbelow the packer and with its rim normally lower than its base portion,and means for flattening out said saucer-shaped member to cause the same.to expand radially as the packer is set in the well.

3. In an oil well packer assembly the combination of a central mandrel,a rubber wall packer mounted thereon, and a shoe mounted on the mandrelbeneath said wall packer, said shoe including a collar fixed to themandreLa ring abutting against the wall packer and a radially expansiblesaucer-shaped member disposed between said collar and said ring with itsrim normally lower than its base portion adapted to expand radially whenforce is applied to the packer to set the same, whereby said radiallyexpansible member provides means for preventing the rubber of the packerfrom flowing or creeping downwardly beneath the shoe.

4. In an oil well packer assembly the combination of a central mandrel,a rubber wall packer mounted thereon, and a shoe mounted on the mandrelbeneath said wall packer, said shoe inl extending slots so that they mayexpand radially when flattened out and provide means for pre venting therubber of the packer from flowing or creeping downwardly beneath theshoe.

JOHN .T. SIMMONS. 1

